The best explanations of cosmic inflation are in cartoon form

Big physics news is often difficult to explain, which, sadly, means it doesn't get explained very well. If you know that, last week, scientists made a major discovery about what happened in the fractions of a second after the Big Bang — but don't understand much more than that — there are two easy-to-digest explainers that will help you wrap your head around the discovery in a bit more depth.

Ph.D. Comics creator Jorge Cham interviewed one of the Ph.D. students working on the team that made the discovery and turned that interview into a cartoon. It'll give you a nice overview of the history behind this new discovery and how it fits into other stuff you've heard about before, like Edwin Hubble and Cosmic Microwave Background Radiation. Then, head over to Minute Physics and watch a short film that focuses in on the discovery, itself. You'll come away with a much better understanding of why physicists are so excited.

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  1. xzzy says:

    Unfortunately stories are coming out casting doubt that the discovery is discovering what it claims to discover.

    Which doesn't mean they're wrong.. just that it's going to take even more discoveries to explain things more fully.

  2. Well, that's a little deflating.

  3. An old mathematics joke

    Two mathematicians were having dinner in a restaurant, arguing about the average mathematical knowledge of the American public. One mathematician claimed that this average was woefully inadequate, the other maintained that it was surprisingly high.
    "I'll tell you what," said the cynic. "Ask that waitress a simple math question. If she gets it right, I'll pick up dinner. If not, you do."
    He then excused himself to visit the men's room, and the other called the waitress over.
    "When my friend returns," he told her, "I'm going to ask you a question, and I want you to respond 'one third x cubed.' There's twenty bucks in it for you." She agreed.
    The cynic returned from the bathroom and called the waitress over. "The food was wonderful, thank you," the mathematician started. "Incidentally, do you know what the integral of x squared is?"
    The waitress looked pensive, almost pained. She looked around the room, at her feet, made gurgling noises, and finally said, "Um, one third x cubed?"
    So the cynic paid the check. The waitress wheeled around, walked a few paces away, looked back at the two men, and muttered under her breath, " a constant."

  4. Here's what I don't get. The further out we look, we see objects (galaxies and earlier and earlier galaxies) moving away from us faster and faster, i.e. red shifted more and more. But these things are in the PAST. So when you look at something in the most distant past (14 billion years) and it is moving away from you faster than things 13 billion years ago, and that stuff faster than things 1 billion years ago... That means that things in the past moved faster than things in the present. Or, in other words, that things were FASTER in the PAST and SLOWER RIGHT NOW.

    So why does everybody say the universe is not only expanding, but accelerating? If it's going faster in the past and therefore slower now, then how can you say that? It's DEcelerating, not accelerating.

    Anyone care to enlighten me?

  5. I'm woefully unqualified --so here goes...

    It's a matter of perspective. What I can grasp (not having the math skills needed) is the Rubber Sheet model explanation. Which is explained on the linked site thus:

    We can imagine galaxies are like balls sitting on a rubber sheet which represents
    space. If we stretch the sheet, the balls move apart. Balls which are close
    together will only move apart slowly. Balls which are widely separated will seem
    to move apart very quickly.

    People living on any one of the balls will see their own ball as stationary.
    They will see nearby balls moving away slowly and they will see distant balls moving
    away quickly. Very distant balls (beyond the horizon) can be moving away faster
    than the speed of light, but the people cannot see them - locally in their own part
    of the universe nothing is travelling faster than the speed of light.

    What I get from this is that the redshifted light is due to the expansion of the space-time fabric between observer (us) and subject (far flung celestial fuzzball). Greater distances = more stretching = more redshift.

    Another way to look at it is with a driving example. I start a journey of 60 miles and travel at 60 miles per hour (as fast as the car is allowed to go). Should take an hour --but there's a catch. The road stretches as I drive. If the stretching is extreme my hour drive could take 13 billion years. If the road stretches at a rate greater than 60 miles per hour, I'll never reach my destination.

    Anyone else? I'm not sure that really answers the question...

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